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IntroductionRenal colic and kidney stones are one of the most common causes of emergency department visits in the United States. While around 70% of these patients underwent CT imaging in the United States as part of their initial workup, our Canadian counterparts prefer bedside ultrasound (also estimated to be around 70%). Do some of these patients even need imaging at all for recurrent stones? And how effective is medical expulsive therapy (MET)? Here we take a look at some new research that may help us change our future practice in providing not only evidenced-based medicine, but also safe, efficient, and cost-effective care.

​The STONE Score – a new clinical prediction ruleThis clinical decision rule out of Yale uses a set of five factors: male sex, duration of pain, non-black race, nausea or vomiting, and microscopic hematuria, to assign a score 0-3 summed to create a STONE score 0-13. The low probability group (score 0-5) predicted the presence of a ureteral stone in 8.3% of the derivation cohort and 9.2% of the validation cohort. The moderate probability group (score 6-9) predicted the presence of a stone in 51.6% and 51.3% respectively. The high probability group (score 10-13) predicted the presence of a stone in 89.6% and 88.6% respectively. In the high score group, acutely important findings (appendicitis, diverticulitis, etc.) were present in 0.3% of the derivation cohort and 1.6% of the validation cohort. (1)

This clinical prediction rule may be no better than a clinician’s gestalt, but it is another reason to argue against repeat CT imaging in a patient with a known stone or history of stones.Ultrasound just as safe as CTCT has been the preferred method of imaging for suspected stones because of the high sensitivity as well as the ability to detect alternative pathologies; however, this has not led to the increase incidence of alternative pathologies. The argument to use ultrasound as the initial imaging modality for the evaluation of suspected kidney stones is that it’s fast and safe; but how safe is it? Apparently, very safe! A multicenter comparative effectiveness trial randomized 2759 participants into three groups: bedside ultrasound, radiology ultrasound, and CT imaging. Other than the obvious less exposure to radiation, there was no difference in high-risk diagnoses with complications in the first 30 days between the groups, no difference in serious adverse events, and pain scores. Another benefit in favor of point-of-care ultrasonography includes decreased length of stay in the ED. (2)​The SUSPEND Trial - does tamsulosin really work to help pass stones?Tamsulosin has been at the forefront of MET and often prescribed for a patient diagnosed with kidney stones and discharged from the emergency department. The idea is that it relaxes the smooth muscle of the ureter leading to ease of stone passage. There’s been many randomized control trials looking at the effectiveness of alpha-blockers such as tamsulosin, but many of these were underpowered. Only 7 out of 32 from a recent Cochrane review were even double-blinded studies.The results of the SUSPEND trial from the UK could be a game changer. This was the largest multicenter, randomized control trial with 1167 participants randomized to three double-blind arms. Patients received tamsulosin, nifedipine, or placebo for single ureteric stones < 10 mm diagnosed by CT. The results showed no change in spontaneous stone passage at 4 weeks for either drug vs. placebo or compared to each other. In addition, there was no difference in additional analgesic use or time to stone passage amongst all groups. (3)How does this change practice? Not prescribing a patient tamsulosin may take away the placebo effect. And while it costs around $20 for a 30-day supply, there’s very few adverse effects from the drug itself. Looking at the subgroup analysis below, it’s interesting to note that while not statistically significant, there is a trend toward favoring tamsulosin for ureteric stones located in the distal ureter.

The DUST trial – tamsulosin might help for larger stones“Hold on, you just told me that tamsulosin doesn’t work for passing stones.” I did, and in fact, the DUST trial confirmed that there was no benefit to giving patients 0.4 mg of tamsulosin daily with distal ureteric stones < 10 mm in terms of time to stone passage, spontaneous passage, or pain requirements. However, in their subgroup analysis, they found that large stones (5-10 mm), tamsulosin did increase passage. This Australian multicenter randomized, double-blinded, placebo-controlled trial took 403 participants and looked only at distal ureteric calculi. Results were followed up within 28 days of an emergency department visit with CT. How can their results be explained? This may be due to the fact that stones less than 5 mm are likely to spontaneously pass anyway, especially if they were in the lower ureter. If anything, this trial somewhat reinforces the trend found in the SUSPEND trial. (4)

​So in conclusion, what have we learned from all this?

Initial bedside ultrasound is a safe and efficient way for evaluating suspended renal colic.

While not discussed in this blog post in detail, NSAIDs do work as analgesia for kidney stones. In fact, it works better than antispasmodics and opioid medication.

Alpha blockers work no better than placebo in the passage of stones. With smaller stones, time will do most of the work and like most things, this too shall pass…

However, alpha blockers may benefit larger stones (5-10 mm) located in the distal ureter for passage.

Its a good information.here i am also share some details about kidney stones.The leading cause of kidney stones is dehydration and due to lack of water in the body, the uric acid can not get diluted easily and as a result of this, the urine becomes more acidic.Know more : https://www.livehomeo.com/treatments/homeopathy-treatment-kidney-stones/

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